All uses of the fchmodat command must be audited.

From Red Hat Enterprise Linux 7 Security Technical Implementation Guide

Associated with: CCI-000172

SV-86733r3_rule All uses of the fchmodat command must be audited.

Vulnerability discussion

Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.Audit records can be generated from various components within the information system (e.g., module or policy filter).Satisfies: SRG-OS-000458-GPOS-00203, SRG-OS-000392-GPOS-00172, SRG-OS-000064-GPOS-00033

Check content

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "fchmodat" command occur. Check the file system rules in "/etc/audit/audit.rules" with the following command: Note: The output lines of the command are duplicated to cover both 32-bit and 64-bit architectures. Only the lines appropriate for the system architecture must be present. # grep -iw fchmodat /etc/audit/audit.rules -a always,exit -F arch=b32 -S fchmodat -F auid>=1000 -F auid!=4294967295 -k perm_mod -a always,exit -F arch=b64 -S fchmodat -F auid>=1000 -F auid!=4294967295 -k perm_mod If there are no audit rules defined for the "fchmodat" command, this is a finding.

Fix text

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "fchmodat" command occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": Note: The rules are duplicated to cover both 32-bit and 64-bit architectures. Only the lines appropriate for the system architecture must be configured. -a always,exit -F arch=b32 -S fchmodat -F auid>=1000 -F auid!=4294967295 -k perm_mod -a always,exit -F arch=b64 -S fchmodat -F auid>=1000 -F auid!=4294967295 -k perm_mod The audit daemon must be restarted for the changes to take effect.

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